1. Technical Field
The present invention relates to a minimally invasive method for cutting, damaging and destroying selected cells or portions of tissue. More particularly, the present invention relates to the use of electrodes to create a plasma spark to cut, damage, and destroy cells or portions of selected tissue.
2. Related Art
The inventors have developed the present invention, which overcomes the drawbacks of prior art techniques and provides a new technique for cutting, damaging, ablating and destroying tissue that does not need to be carried out in a specialized medium, operates at low energy, and minimizes collateral damage to surrounding tissue.
Treating tissue using electrical discharge from an electrosurgical device has been the subject of investigation for many decades. This type of treatment has been used, for example, during standard open surgical procedures and procedures using probe-like devices that may be easily inserted into cavities and regions within a patient for minimally invasive procedures. Traditionally, the devices used in these techniques required the introduction of a conductive medium (either liquid or gas to generate a discharge). This requires relatively large incisions and use of circulated liquids or gases, which introduced further complications and risks. Previous devices and techniques have the potential to cause electrical burns to the tissue at the ground plate due to leakage currents. One reason for this problem is that most of the prior art devices used the tissue, e.g., skin, as the second electrode in the device.
An additional disadvantage of the prior art is that the tissue cuts were achieved by burning the tissue, which caused collateral damage to the surrounding tissue. The techniques disclosed in the prior art typically apply monopolar or biopolar radiofrequency energy. In monopolar applications electric current flows unpredictably and can produce unwanted tissue heating or stimulation. With conventional monopolar and bipolar electrosurgery techniques, high temperatures on the order of a few hundred degrees are reached with concomitant heating of surrounding tissue due to heat diffusion leading to collateral damage to surrounding tissue. In many electrically induced plasma based techniques, another medium such as saline solution is introduced near the target tissue. The addition of another medium, however, makes the procedure more cumbersome. It would be preferable if the tissue itself were to be cut without introduction of an external medium.